When I was chosen as one of the two human players to defend mankind against Watson, IBM's "Jeopardy!"-playing supercomputer, I was keenly aware of the grave responsibility being placed on my shoulders. I imagined myself as John Connor, the dauntless hero of the "Terminator" films, bravely leading the resistance against our new digital overlords for generations to come. In the end, of course, Watson's dominating performance put the match away early, and it went on to a lopsided (Ken Jennings-like, a less modest observer than myself might say) "Jeopardy!" victory. I wound up being a 21st century John Henry, the "steel-driving man" sent to an early grave in his very first encounter with his mechanical replacement.

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But what "Jeopardy!" fans saw on TV this week wasn't the whole story.

Watson is indisputably a huge leap forward in computer "thinking." When I studied artificial intelligence in college just a decade ago, a question-answering computer as flexible and sophisticated as Watson would have been snorted at as science fiction - the kind of technology that only Captain Kirk, not Alex Trebek, would have access to.

But is it really head and shoulders above the best human "Jeopardy!" players, the way it looked on TV? Not by a long shot.

The key to Watson's dominance lies in the famously tricky "Jeopardy!" buzzer, the signaling device that allows players to respond to the show's clues. Like any human player, Watson does buzz with a "thumb" of sorts (actually a magnetic coil mounted over a buzzer), but it can also rely on the millisecond-precision timing of a computer. The reflexes of even a very good human player will vary slightly, but not Watson's. If it knows the answer, it makes the perfect buzz. Every single time. And it's hard to win if you can't buzz. Imagine if John Henry had to beat the steam engine at a feat of brute strength just to be allowed to swing his hammer, or if chess grandmaster Garry Kasparov had to solve a long-division problem faster than supercomputer Deep Blue every time he moved a piece in their epic match.

And Watson had the advantage of playing two humans at once. Because of Watson's superhuman timing, it answers nearly all of the clues it decides to attempt. Then the two human contestants have to fight over the leftovers. Even worse, the third player in the Watson match wasn't some run-of-the-mill runnerup from college "Jeopardy!" (or, even more remedially, from celebrity "Jeopardy!"). It was Brad Rutter, the man who had racked up more than $3 million in "Jeopardy!" winnings while never losing a game, my own personal quiz show nemesis.

With its 15 trillion-byte data bank of human knowledge and its ability to defuse the full arsenal of weapons used in tricky "Jeopardy!" clues (wordplay, double meanings, elliptical hints), Watson is admittedly a very smart cookie. But it's far from infallible. In an average "Jeopardy!" game, it gets stumped many more times than top-level human players do, and relies on its buzzer advantage to pick up the slack. Sometimes its misses are so elegantly wrong that they approach performance art. When asked what grasshoppers eat, it once confidently answered, "What is kosher?" - and later claimed that the Russian word for "goodbye" was "cholesterol." In a practice round I watched, Watson was asked what paper towel brand is pitched by a lumberjack. The computer was torn between two answers: "Brawny" and "Jesus Christ."

And despite Watson's 2,880 processor cores working in parallel, it's slower than the human brain as well. In a category about "Actors Who Direct," Watson fell apart. The clues were so short ("The Great Debaters" led to the response "Who is Denzel Washington?" for example) that Watson came up with the (correct) responses long seconds after Brad or I had already buzzed in.

Watson's programmers call Achilles' heel categories like these "train-wreck categories." In practice rounds, when Watson hit one or more "train wrecks," it was toast - Brad and I each beat it once handily. But in the televised matches, Watson got a good draw of categories, leading to an easy win.

So take heart, fellow carbon-based life forms! Watson may be an intimidating quiz show presence, but it needed more than smarts to get the win. It also needed superhuman reflexes, a divided opposition and a little luck. Just because a "Jeopardy!" contestant "died with his buzzer in his hand," like John Henry, doesn't mean humanity is obsolete quite yet.

Jennings, who won 74 straight "Jeopardy!" games, is author of the book "Braniac."